<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>5</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }
        .parent {
            width: 500px;
            height: 500px;
            background-color: pink;
            left: 100px;
            top: 100px;
            position: absolute;
        }
        .child {
            width: 300px;
            height: 200px;
            background-color: blue;
        }
        .box {
            width: 100px;
            height: 100px;
            background-color: green;
        }

    </style>
</head>
<body>
    <div class="parent">
        <div class="child"></div>
    </div>
    <div class="box">hello world</div>
    <script>
        const oParent = document.querySelector('.parent');
        setTimeout(() => {
            oParent.style.position = 'static';
        }, 5000);
    </script>
</body>
</html>